Refractory material.



' oaasaa.

- No Drawing.

FRANK J. TONE, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TO THE CARBORUNDUMCOMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION OF PENNSYLVANIA.

REFRACTORY MATERIAL.

Specification of Letters Patent.

To all whom it may concern:

Be it known that T, F RANK J. TONE, of

Niagara Falls, Niagara-county, New York,

have invented a new and useful Improvement in Refractory Materials, ofwhich the following is a full, clear, and exact description.-

This invention relates to the use of carborundum as a refractorymaterial, and es- ,pecially refers to a method of using the same, as asolid lining material for furnaces. My invention will be best understoodby describing its application in the construction of a tilting meltingfurnace such as is commonly used in the melting of brass, and.

heated by oil or gas. Such a furnace consists of an iron or steel shelllined on the inposing the lining which will meet the spe-' cialrequirements of this work. When carborundum is used for this purpose itmust be mixed with a suitable binder, and pressed and rammed into placein the shell. It must then be dried out and fired. As one side of thelining is in contact with or in close proximity to the steel shell ofthe furnace, it cannot be highly heated at this point without fusing theiron; the interior on the other hand must be brought up to the hightemperature of the oil flame. In order to exert proper binding actionunder these extreme conditions of temperature, the binder used mustpossess peculiar properties, and therefore, I propose to have therefractor material include a bond which is most efilictive at a hightemperature so as to prevent disintegration of the inner portion of therefractory' lining which is directly exposed to the heat of the furnace,and another bond which is most efiective at a relatively lowtemperature, so as to prevent disintegration of the outer surface of therefractory lining. While the bond which is most effective at arelatively low temperature may become destroyed in the highly heatedportions of the.- g Y lining, it becomes a flux when highlyheated andunites with the other bond, which Ina-- terially increases the bindingpower of the latter. It is therefore apparent that, while the two bondsare designed to respectively meet the conditions of the lining at itsinner face and at its outer face, they are also des1gned to combine andincrease the efficiency of the bond which is primarily designed formeeting the conditions at the inner surface of the lining. l havediscovered that a mixture of carborundum, fire clay and silicate of sodaof proper proportions, meets the conditions in a satisfactory manner.sesses considerable binding properties when merely dried out in the air;when heated to from 400 to 600 Fahn, its full binding property isdeveloped; when heated to white heat, its chemical composition changesand its binding power may in cases be destroyed. Fonthis reason, theaddition of fire clay is found advantageous, its binding power beingonly fully developed at white heat and the soda from the decomposedsilicate acting as a flux to fuse the clay. The grades of silicate ofsoda which I have found most suitable for this work are from 47 to 50Baum. The presence of the clay in the cooler portions of the lining doesnot detract froin the binding properties of the silicate of soda, and inthe hotter portions of the lining the bond is due to the clay fluxed ina certainmeasure by the soda. The mixture of these two binding materialsthere fore provides a bond which is satisfactory for a wide range oftemperature.

It will of course be understood that the present invention is of plasticmaterial capable of being handledby means of a trowel or the like andthereby conveniently applied to the interior of the furnace and moldedtherein to assume the desired shape.

The carborundum employed may be amorphous carborundum (sometimes knownas siloxicon or white-stuff), or crystalline carborundum may be used.

In the practice of my im ention I may use the ingredients in variousproportions as determined by the thickness of the lining and thelimiting temperatures. tained good results by a mixture consisting of 80parts carborundum, 10 parts fire clay, and 10 parts silicate'of soda;and I deem these to be the preferable proportions. T

I have ob- Patented Oot.29,1l91l2. Application filed'Apr'il 25, 1905.Serial No. 257,319.

Silicate of soda is a binder which pos- "mixture forming a selfsustaining refractory compound; substantially as clescribecl, 52. 1%..plastic refractory furnace lining, including carborunclum as the majorportion thereof, a boncl Which is relatively more effective at arelatively high temperature, and another boncl which is most effectiveat a relatively len temperature, the latter bonrl being present in aproportion of not over fifteen per cent. of the lining the noaaseaforming a self sustaining refractory com pouncl; substantially asdescribedl.

3. A plastic refractory furnace lining, in cluding carborundum as themajor portion thereof, a bond which is most efi'ective at a relativelyhigh temperature, and another boncl consisting of silicate of sodacomprising not over fifteen per cent, of the lining so the mixtureforming a self-sustaining refractory compound; substantially asolescribed I i. As a new composition of matter, a selfsustaining plasticrefractory furnace lining 35 material, composed of cz-nlglaty partscarborunoluin, ten parts fire clay, anrl ten parts 5 silicate of socla;substantially as clescriberl. ltn testimony whereof, l have hereunto setmy hand. all, Witnesses: flSHMEz-lii G. Ronenns,

Fnann L,

